Boxing and MMA fans are gearing up for what could be a real-life fantasy boxing matchup between undefeated boxer Floyd “Money” Mayweather and UFC lightweight champion Conor McGregor. Mayweather, who would need to come out of retirement for the fight, holds a 49–0 career professional boxing record and won world titles in five different weight classes. McGregor recently became the first UFC fighter in history to hold simultaneous championships in two different weight classes.

Some sports fans had dismissed the cross-promotional superfight as nothing more than a pipe dream, but Mayweather told EPSN’s Stephen A. Smith this week that the “we are getting very, very close” to a deal.

If McGregor and Mayweather can agree to terms, the fight could be even bigger for Las Vegas than the clash between Mayweather and Manny Pacquiao back in 2015.

The Mayweather/Pacquiao fight was hosted by the MGM Grand Garden Arena, and the telecast was a joint production between CBS Corporation (NYSE: CBS)’s Showtime and Time Warner Inc (NYSE: TWX)’s HBO.

Following the ESPN story about the fight, Mayweather posted on social media that there have been “no deals made on my behalf in regards to a bout with any fighter at this time.” In addition, McGregor posted photos of himself in Las Vegas and wrote, "I am in Las Vegas. Floyd has retired on my arrival.”